Rambo 5 revolves around Rambo fighting his way through human traffickers and drug lords to rescue a young girl abducted near the U.S.-Mexico border."
Filming should start in Spring 2010, so the release date of Rambo 5 is most likely early 2011, or December 2010 if we are lucky.

Please take all the time you need while developing this movie: if Rambo 5 is closing the Rambo movie series it has to be the best Rambo movie ever!